[
https://issues.apache.org/jira/browse/YARN-6357?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15936727#comment-15936727
]
Vrushali C commented on YARN-6357:
----------------------------------
In the write APIs, I think it will be good to have an explicitly named async
API and a sync API (rather than persistXX).
I think the API doc should explain that the sync one means syncing to call
HBase flush and that aysnc means it will be translated to hbase#flush after a
time interval or at the end of the application life.
> Implement TimelineCollector#putEntitiesAsync
> --------------------------------------------
>
> Key: YARN-6357
> URL: https://issues.apache.org/jira/browse/YARN-6357
> Project: Hadoop YARN
> Issue Type: Sub-task
> Components: ATSv2, timelineserver
> Affects Versions: YARN-2928
> Reporter: Joep Rottinghuis
> Assignee: Haibo Chen
> Labels: yarn-5355-merge-blocker
> Attachments: YARN-6357.01.patch, YARN-6357.02.patch
>
>
> As discovered and discussed in YARN-5269 the
> TimelineCollector#putEntitiesAsync method is currently not implemented and
> TimelineCollector#putEntities is asynchronous.
> TimelineV2ClientImpl#putEntities vs TimelineV2ClientImpl#putEntitiesAsync
> correctly call TimelineEntityDispatcher#dispatchEntities(boolean sync,...
> with the correct argument. This argument does seem to make it into the
> params, and on the server side TimelineCollectorWebService#putEntities
> correctly pulls the async parameter from the rest call. See line 156:
> {code}
> boolean isAsync = async != null && async.trim().equalsIgnoreCase("true");
> {code}
> However, this is where the problem starts. It simply calls
> TimelineCollector#putEntities and ignores the value of isAsync. It should
> instead have called TimelineCollector#putEntitiesAsync, which is currently
> not implemented.
> putEntities should call putEntitiesAsync and then after that call
> writer.flush()
> The fact that we flush on close and we flush periodically should be more of a
> concern of avoiding data loss; close in case sync is never called and the
> periodic flush to guard against having data from slow writers get buffered
> for a long time and expose us to risk of loss in case the collector crashes
> with data in its buffers. Size-based flush is a different concern to avoid
> blowing up memory footprint.
> The spooling behavior is also somewhat separate.
> We have two separate methods on our API putEntities and putEntitiesAsync and
> they should have different behavior beyond waiting for the request to be sent.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
---------------------------------------------------------------------
To unsubscribe, e-mail: yarn-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: yarn-issues-h...@hadoop.apache.org
